Trade in the Carver for something like a B&K st140 used and have it modified by Musical concepts. Upgrade your interconnects and cable. If your cd player has a digital out get an outboard DAC This all should cost less than $1K.
Sheffield, Don't even consider changing your PSB Stratus Golds.You would have to spend 5k to improve what you already have.I have the Stratus Silvers(I used to have Golds)and I just added a EVS Millenium 2 DAC,with a volume control on the back.I have a Classe CA-100 amp.The new sound was jaw dropping.You could buy a new DAC 2 for 1050.00 and spend 1500.00 on a new amp.Take your pick,for 1500.00 used you could get a big league amp.You have a nice pre amp.If you don't want the DAC,spend the extra loot on a nice amp.The Carver's your only weak point.The tweaks suggestion was good stuff too.Good luck!!
start from carver first and get Bryston 3b-st or 4b-st which I believe will be the best value investment. Both of these amps have 20yr warranty, built like a tank, have enouhg power to drive PSBs and can get you closer to the music.
I'm using a similar system and found a couple of tweaks to help. First, I put a new powercord on my McCormack DNA-225 which created more bass power in the PSB's. Second, I bi-wired the PSB's with Nordost Super Flatline Mk II. I heard mixed reviews of doing this, but for me it helped open the PSB's up. Third, I put AIG rings ($14) around the tweakers. This created a bit more focus in imaging. Fourth, I took the speaker covers off the speakers and toed them in a bit. Lastly, a probably most importantly I upgraded my sources significantly. Cambridge Audio CD4SE to Naim CD5 and Music Hall MMF-5 to Michell Gyro SE. This was the most significant improvement. More than changing pre-amp or moving from integrated amp to a big amp. Hope this helps.